Fix webrtc copyright boilerplate

Issue description

Our copyright boilerplate should look like this:
Copyright <year> The WebRTC Project Authors. All rights reserved.
It's currently:
Copyright (c) <year> The WebRTC project authors. All Rights Reserved.
We should fix all files in one go, then adjust the presubmit checks to not allow the old format.
Corresponding Chromium issue here:
http://code.google.com/p/chromium/issues/detail?id=140977

This issue has been Available for over a year. If it's no longer important or seems unlikely to be fixed, please consider closing it out. If it is important, please re-triage the issue.
Sorry for the inconvenience if the bug really should have been left as Available.